function setCookie(name, value) {
   var nrDays = (arguments.length > 2) ? arguments[2] : 31;
   var path = (arguments.length > 3) ? "/"+arguments[3] : "/";
   var expiryDate = new Date();
   expiryDate.setTime (expiryDate.getTime() + (nrDays * 60 * 60 * 24 * 1000));
   document.cookie = name.toLowerCase() + "=" + escape(value) + ";path=" + path + ";expires=" + expiryDate.toGMTString(); // + ";";
}

function getCookie(name) {
   var numOfCookies = document.cookie.length;
   var nameOfCookie = name.toLowerCase() + "=";
   var cookieLen = nameOfCookie.length;
   var x = 0;
   while (x <= numOfCookies) {
      var y = (x + cookieLen);
      if (document.cookie.substring(x, y) == nameOfCookie)
         return valueOfCookie(y);
      x = document.cookie.indexOf(" ", x) + 1;
      if (x == 0)
         break;
   }
   return null;
}

function valueOfCookie(val) {
   if ((endOfCookie = document.cookie.indexOf(";", val)) == -1)
      endOfCookie = document.cookie.length;
   return unescape(document.cookie.substring(val, endOfCookie));
}

function deleteCookie(nameOfCookie) {
   if (nameOfCookie == "")
      document.cookie = "";
   else {
      var yesterday = new Date();
      yesterday.setDate(yesterday.getDate() - 1);
      document.cookie = nameOfCookie.toLowerCase() + "=; expires=" + yesterday.toGMTString() + "; path=/;"
   }
}